I have a Pioneer PDP-505HD that wont power up. There is a high pitch whine coming from the power supply when you try to power on. Does anyone know what usually causes this or a schematic possibly. The 5v stand by at test point 111 is reading 4.97v and the 12v stand by at test point 112 reads 16.44v. I've checked most of the caps with the capacitor wizard and they check ok. D439 lights up on the PCB after about 5 seconds after you hit the power button and the fans all stop as well. I believe there is a bad NEC buffer board only because I had seen a small burn on that board after it ran with a ribbon cable unplugged. I think the buffer board is another issue I may have caused myself but my main concern in this post is the SMPS as I need the set to power up before anything. This set didnt power up before that had happened anyway.

Wow thats an amazing website! I got too excited and paid 9.99 for the service manual before I waited long enough to see if someone had it, but the info to the website you provided me is worth that again and again. Thanks so much for your help. This has been one of the tough dog repairs for me but I'll post results if I can get em. Thanks again...